Seems to me the subject of marriage, and your insistence on it, is a one way street for you.

Me personally, if I see someone more than once, I commit to that person. I don't date anyone else during that time because I want to know that particular person and have interest in only being with THAT person.

Also, being agnostic leaning toward atheist, marriage is a religious and government institution. If there are no tax benefits to marry then why do it? Not to say I wouldn't but it certainly isn't a requirement for me. I can and do commit to someone without making promises and expecting to do right by some imaginary deity.